Natural radioactivity assessments and radiological hazards in agricultural soils around mining activities in Karibib, Namibia

A total of 17 soil samples were randomly collected from agricultural farms around mining areas from Karibib, Erongo region, Namibia. The samples were analyzed for natural radioactivity using a high purity germanium (HPGe) detector. The average activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K were 80.80, 73.60, and 493.96 Bq.kg ^{– 1} respectively. The radiological assessments were calculated in terms of radium equivalent activity (224.09 Bq.kg ^{– 1}), absorbed dose rate (102.39 nGy h-¹), annual effective dose equivalent (indoor and outdoor) (1.26 mSv y ^{– 1} and 5.02 mSv y ^{– 1}) and the internal and external hazard indices (0.61) and (0.82) respectively. The average values of ²²⁶Ra, ²³²Th and ⁴⁰K were higher than the world average values as well as those of the radiological parameters of absorbed dose rate and annual effective dose equivalent. The average values of radium equivalent activity, and the indices radiological hazards were below the internationally acceptable limits.